My feedback is +1, as it provides a powerful tool for controlling the size of the API one wants to call (client) or implement (server), while also offering future extensions (adding exclusion rules applied after inclusion, allowing operation-level granularity of filtering, and adding equivalent CLI options), based on real-world needs from adopters.
Following some discussion on the pull request[1] with @porglezomp, I think that we want to include filtering at the operation level (cf. path) from the start. I have updated the proposal to bring that part forward from the "Future directions" section into the proposed changes and updated the PoC branch with an implementation[2].
@Honza_Dvorsky, as this feedback was incorporated pretty late in the review period, I'm proposing we extend it for a few days to give folks an opportunity to consider the updates.